The present invention relates to an apparatus and method for providing automated ground exclusion balance in portable hand-held metal detectors of the induction balance transmit/receive type in popular use today for searching and finding metal objects lying on or buried just beneath the surface of the ground. Such detectors are held by the operator and moved or swept over the surface of the ground, and, when the detector passes over a metal object, the disturbance of a magnetic field created in the area of the detector's search loop, as generated by a transmit coil signal and monitored by a receive coil, unbalances the coil loop circuit and causes the detector to produce a visual or audible indication of the presence of the metal object. Such instruments have in recent years become quite sophisticated in operation, sufficiently so that, by responding not only to the amplitude of the magnetic field disturbance but also to the shift in the phase angle of the received or target signal relative to the transmitted signal, an approximate indication can be provided by the detector as to the type of metal object located, e.g. coins as opposed to aluminum pull-tabs, and even as to the type of metal coin involved, penny, nickel, dime, quarter, etc. However, before utilizing these detectors to search for and locate metal objects it is first necessary to adjust the loop circuit to screen out the effects of the mineralized ground in the area. The compensation or adjustments to the detector's search head loop circuit for such earth effects, referred to herein as "ground exclusion balance" or, more simply, "GEB," was commonly carried out prior to the present invention by cut-and-try manual techniques in which the operator would first reset the detector instrument in air to cancel all offsets and to set a low but discernible audio tone level in the detector, and then hold it on or just above a patch of ground known or believed to be free of metal objects. The change from air to ground typically would cause either a marked decrease or increase in the audio tone, and the operator would next respond by changing, through manipulation of a knob setting on the instrument, the parameters of its detector circuitry to change the tone level in the opposite direction. The operator would then repeat the reset step, again change the ground balance setting, and continue this sequence as many times as necessary until the change in tone level in going from air to ground, or back, was either eliminated or reduced to an acceptable minimum level. Such manual GEB adjustment, as can readily be appreciated from the foregoing description, was tedious and time-consuming, and the procedure had to be repeated whenever the mineralization content of the ground changed appreciably as the operator worked over an area.